First Trimester Screening, sometimes referrred to as Early Screening or Ultra-Screen, is a blood test combined with an ultrasound exam that is used to identify pregnancies at increased risk for three chromosome abnormalities: Down syndrome, Trisomy 13, and Trisomy 18. The ultrasound is necessary to obtain a nuchal traslucency measurement, the measurement of a fluid-filled space at the back of the fetal neck. In addition to this measurement, our ultra sonographers are two of the few individuals in the state who are certified in examining the nasal bone, which increases the detection rate. It is important to note that the results from this testing are not diagnostic. First trimester screening can be completed between 11 weeks and 13 weeks gestation. Because this testing does not screen for such birth defects as neural tube defects, it is recommended that a maternal serum alpha-fetoprotein (AFP) level be drawn separately between 15 and 20 weeks gestation. An anatomy ultrasound in this same time frame can also be used to screen for neural tube defects as well as other anomalies.